Small pin/large pin? Help?

[Birddog1911]

I'm about to build a lower for my Mk12, and I'm looking at the Rock River Arms NM trigger, and it states that it is small pin. Now, is that the standard that you find when buying a lower receiver, or is this something I have to be sure about before I purchase?

[Hoser]

Colts use large pins. Everyone else for the most part uses small pins.

[Hoser]

and I'm looking at the Rock River Arms NM trigger,

Get a Geissele instead. Trust me.

[Birddog1911]

Truly worth the cost? I was thinking RRA NM for the durability aspect; heard from a couple of folks that some of the match triggers are a little delicate.

[ray1970]

As stated before, small pins are the norm (mil-spec) and only Colt uses the large pins. The Gieselle triggers must be pretty awesome. I know a guy that many AR rifles and he has tried just about every trigger ever made by anyone. I think every one of hifles currently has a Gieselle trigger in it.